Practices on precision gas pre-drainage based on time-space attribute in Huangling Mining Area

In order to realize a precision gas pre-drainage in Huangling Mining Area, based on the comprehensive analysis on the coal mine gas content distribution law, the relationship between the effective gas drainage radius and the gas drainage time as well as the “mining-excavation-drainage” connection relationship, from a view of the time and space, a pre-gas drainage borehole was provided to the precision gas pre-drainage method in a underground coal mine with sectional layout. A site demonstration test was conducted on No. 207 fully-mechanized coal mining face in No. 2 Mine of Huangling Mining Area. The test results showed that the borehole sectional layout plan of the method provided could effectively solve the blank zone of the gas drainage and the gas drainage to reach the target. This sectional layout plan was obviously better than two plans with the general borehole spacing of 6 m and 12 m individually. In comparison with the two plans, the sectional layout plan could individually save the gas pre-drainage time of 36 days and 146 days and could effectively release the connection unbalanced of the “mining-excavation-drainage”.The economic benefits of the sectional layout plan was obvious and the precision gas pre-drainage in the underground mine was realized.